Sunroom vs Conservatory vs Orangery in Ireland: Cost & Which to Choose

Last updated: 29 July 2026 · By Mossy Tariq, Founder — Property Blueprint Co.

Three showrooms will quote you for what looks like the same glass room, and give it three different names: a sunroom, a conservatory, an orangery. The prices come back anywhere from about €15,000 to well past €40,000, and most homeowners assume the gap is finish, or brand, or negotiation. It is almost never any of those. The difference is built into the roof and the walls, and it is the one thing that decides whether the room actually works.

Comparing a sunroom vs conservatory vs orangery is a construction choice, not a style one — how much of the shell is glass and how much is solid — and that single distinction drives the three things that matter most in Ireland: what it costs, whether it is warm enough to sit in during a wet February, and how it lands on your BER. Get the roof wrong and you have paid five figures for a room you use four months a year.

This is the framework the showroom is not built to give you — it sells the structure it builds best.

The label on the brochure does not decide whether you use the room in winter. The roof does.

What is the difference: sunroom vs conservatory vs orangery?

The three sit on a single spectrum, measured by how much of the shell is glazed. From most glass to least, you move from conservatory, to orangery, to sunroom.

A conservatory is the most glazed — by convention, more than roughly 75% of the roof and 50% of the walls are glass, typically a fully glazed pitched roof on a low brick base in uPVC or aluminium. It is the cheapest to build and the brightest to sit in, and it behaves like a greenhouse: quick to overheat in sun, quick to lose heat on a cold night.

An orangery sits in the middle — masonry-led, with brick or stone piers and solid walls, large windows, and a flat perimeter roof pierced by a central glazed lantern. The brick holds heat, the lantern brings light down the centre, and it reads as a permanent room. It is also the dearest of the three, because it is closest to a conventional extension.

A sunroom is the least glazed. It keeps large windows but replaces the glass roof entirely with a solid, insulated, tiled or slated roof — the same build-up as the rest of the house. That one change is the whole difference: an insulated roof is what separates a room that holds temperature from a room that does not.

What does each one cost in Ireland?

Ireland has no official price list for these structures; any figure you are quoted is a market estimate, not a published rate. The reliable anchor is the per-square-metre build cost quantity surveyors apply to a rear extension, broadly €2,000 to €3,900 per square metre for a mid-range finish in 2026, Dublin at the top of that band. Read the three structures as points along it.

A basic uPVC conservatory is the entry point and usually lands below that rate, often from around €15,000 to €25,000 for a modest room, because it is largely a prefabricated glazed kit. A solid-roof sunroom built to a habitable standard costs more, toward the middle of the extension rate. An orangery, with its masonry piers and lantern roof, prices like the small extension it effectively is — routinely €35,000 and up. Treat these as indicative Irish market bands, not authority figures; the honest number comes from your specification, not the label.

The trap in every quote is what is excluded. Foundations on sloping ground, drainage diversions, the structural beam where the room meets the house, electrics, heating, flooring and the VAT treatment are the line items that become a variation later. You also carry rights under the Consumer Rights Act 2022 when you engage an installer, and the CCPC sets out the standard you are entitled to. Set your own trade-by-trade baseline first, so you can see which quote is genuinely cheaper and which has left more out.

Our guide to how much a sunroom costs in Ireland breaks down those line items, and the garden renovation cost guide covers the groundworks that often come with the project.

Which suits the Irish climate and your BER?

This is where the three separate for good, and the section a showroom rarely leads with. The Irish climate is not a summer-room climate — mild, damp and grey for much of the year — so the real test is not how the room feels in July but whether you sit in it in January. That is a question about the roof, answered by physics.

A fully glazed conservatory loses heat through every surface and overheats under direct sun; without high-specification glazing it is a shoulder-season room. A sunroom, with its insulated solid roof, holds heat like the rest of the house and is usable year-round. An orangery lands between the two.

The energy question is also a compliance and resale question, through your BER. Under the Building Regulations, Technical Guidance Document L does not treat a conservatory as a special case: it is regarded as an extension and must meet the same fabric standards — including current worst-case wall and pitched-roof U-values of 0.21 and 0.16 W/m²K — unless it is separated from the house by external-quality walls and doors, intended for occasional use, and either unheated or independently heated. A solid roof can meet that standard. A glass roof cannot.

The consequence is the part homeowners miss. Open the room to the kitchen and put a radiator in it, and it is no longer separated, so it counts toward the assessed dwelling for your BER — where a large glazed area loses heat and pulls the rating down. A properly insulated sunroom folded into the heated house does not. The Sustainable Energy Authority of Ireland (SEAI), which administers the BER, treats that thermal separation as the pivot.

Do you need planning permission in Ireland?

Often you do not — but the exemption is conditional, and the conditions changed days ago. A rear extension, and the Regulations name a conservatory explicitly, can be built as exempted development without planning permission if it stays inside every condition. On 27 July 2026, new Exempted Development Regulations raised the headline limit: a rear extension is now exempt up to 45 square metres of floor area, up from the long-standing 40. Because the change is only days old at the time of writing, confirm the current position with your own local authority before relying on it.

The size cap is only the first condition; the rest are what catch people out:

• The 45 square metres is cumulative — it includes every extension built since 1 October 1964, permitted or not, and the new room counts toward it too.
• The extension must not be higher than the existing house.
• It must not reduce the private open space at the rear — the garden reserved for the occupants — to less than 25 square metres.
• There are conditions on windows and boundaries, and above-ground-level work is far more restricted.
• Exempted development is a planning exemption only. The room must still comply in full with the Building Regulations.

Miss a single condition and the whole exemption falls away, at which point the room needed permission you never sought. A protected structure or a house in an Architectural Conservation Area removes the exemption outright. If in doubt, apply to your local authority for a Section 5 declaration before you commit. The conditions are set out on Citizens Information, and our guide to planning permission for a renovation in Ireland covers where the wider exemptions end.

Which one adds the most usable, year-round space?

Usable is the operative word. Bright square metres you abandon each winter are not usable space; they are storage with a view. On year-round usability the order is clear — sunroom, orangery, conservatory — because that is the order of thermal performance. But cost runs the other way, and planning and BER sit on top, so the right structure is the one that survives all four filters at once. Work through them in order.

1. Decide how you will use the room, and in which months. A summer breakfast room and a genuine second living room are different briefs, and the brief decides the roof before any quote is discussed.
2. Choose the roof against your climate and BER. If the room will be heated and open to the house, a solid insulated roof — a sunroom or an orangery — is the only choice that will not cost you on your BER and on running cost every winter.
3. Set the budget against the Irish per-square-metre benchmark. Price the room at the extension rate, not the kit-conservatory headline, and hold back at least 12% for the groundworks and structural connection that quotes routinely exclude.
4. Confirm the planning position before you sign. Check the cumulative 45-square-metre total against every previous extension, verify the 25-square-metre garden and the boundary conditions, and lodge a Section 5 declaration if there is any doubt.
5. Read every quote for exclusions, not just the bottom line. Compare quotes line by line so a low headline price hiding an excluded beam, drain or heating circuit is exposed before it becomes a variation on site.
6. Match the structure to the house, not the brochure. An orangery reads as permanent on a period home; a sunroom disappears cleanly into most modern houses; a conservatory that clashes with the house dates fastest and adds least at resale.

Run honestly, that sequence points the year-round buyer at a sunroom or a well-built orangery, and the summer-room buyer, eyes open, at a conservatory. The failure is not choosing a conservatory; it is choosing one while believing you have bought a room you will use in February. This is the operator's view the room-by-room Renovation Blueprint systems are built to give — the logic of The 12-Phase System: decide the brief and specification before the quotes, so every trade prices the same room.

If the cost baseline is the right first step, use the free Renovation Cost Calculator — a trade-by-trade estimate for your specific room, in under 5 minutes, before any showroom has quoted.

Frequently asked questions

What is the difference between a sunroom, a conservatory and an orangery?

It is how much of the structure is glazed. A conservatory is the most glass — a fully glazed pitched roof on a low brick base. An orangery is masonry-led, with brick piers and a flat roof pierced by a central glazed lantern. A sunroom keeps large windows but has a solid, insulated, tiled roof instead of glass, which makes it usable year-round. The roof, not the name, is the real distinction.

Which is cheapest in Ireland — a sunroom, conservatory or orangery?

A basic uPVC conservatory is normally the cheapest, often from around €15,000 to €25,000 for a modest room, because it is a prefabricated glazed kit. A solid-roof sunroom costs more for its insulated roof and better glazing. An orangery is the dearest, routinely €35,000 and up, because its masonry piers and lantern make it effectively a small extension. These are indicative market ranges, not published rates.

Do I need planning permission for a conservatory or sunroom in Ireland?

Often not. A rear extension, including a conservatory, is exempted development up to 45 square metres as of 27 July 2026 (up from 40), if the total is cumulative across all extensions since 1964, the room is not higher than the house, at least 25 square metres of rear garden remains, and window and boundary conditions are met. Building Regulations still apply. If in doubt, apply for a Section 5 declaration before you build.

Does a conservatory affect my BER?

It can. If a glazed room is separated from the house by external-quality walls and doors and is unheated or independently heated, it sits outside the assessed dwelling. Heat it and open it to the house and it counts toward your BER, where a large glazed area loses heat and pulls the rating down. A properly insulated solid-roof sunroom does not carry the same penalty. SEAI, which administers the BER, treats this thermal separation as the deciding line.

Which adds the most value and usable space year-round?

For year-round use the order is sunroom first, orangery second, conservatory last, because that is the order of thermal performance. At resale, an orangery reads as permanent on a period home and a sunroom integrates cleanly into modern houses, while a conservatory that clashes with the house dates fastest and adds least. The most usable room is the one whose roof lets you sit in it in winter.

Is a sunroom just a conservatory with a solid roof?

Effectively, yes — and that one change is the whole point. Replacing a glazed roof with a solid, insulated, tiled roof turns a shoulder-season conservatory into a room that holds temperature like the rest of the house, meets the Part L fabric standard, and can be used all year without a running-cost or BER penalty. The solid roof is not cosmetic; it decides how many months the room is worth having.